Filling spaces or cavities which are difficult of access with concrete, cement, or the like



A. FRANCOIS. FILLING SPACES 0R CAVITIES WHICH ARE DIFFICULT OF ACCESS WITH CONCRETE, CEMENT, OR THE LIKE.

APFLICATION FILED MAY 20| I918- 1,391,678. Pate tedSept. 27,1921.

I u-x-n-l-n subject of the Kin of Belgium, residing at.

UNITED STATES- PATENT OFFICE,

' 41.3mm rnmeors, or DONOASTER, ENG aNn,

FILLING SPACES OR CAVITIES WHICH ARE DIFFICULT OF ACCESS WITH CONCRETE,

CEMENT, OR THE LIKE.

Application filed May 20,

To all whom it concern:

Be it known that I, ALBERT FRANgoIs, a

Whitehouse Cham ers, High street, Doncaster, in the county of York, England, have invented certain new and useful Improvements in Filling Spaces or Cavities Which are Diflicult of Access,with Concrete, Ce-

ment, or the like, of which the following is a specification. t

This invention relates to the filling of spaces or cavities which are difiicult of acthe object being to accomplish this result in v down naturally through oess (such for example as large fissures in the ground,'crevices behind walls or pit tubbings which cannot be treated by hand methods) with concrete, cement or the like,

a ra id and economical manner.

'eretofore in mining or foundation work I where such cavltles are met with and when the circumstances permit of its use it has been proposed to employ a filling material such as concrete which is allowed to siphon ipes from the mixing apparatus. When, however, siphoning cannot-be carried on, a piston or ram pump is employed to generate the pressure neces sary to force the filling material into the cavities but as concrete cannot be employed in a ram pump a finely ground or liquid cement must'be employed. The operation of filling by siphoning, while admitting of the use of a comparatively cheap filling material such as concrete is open to the objection that if ordinary concrete is employed the material while bein fed through the system of pipes is liab e to separate by gravity into different constituent layers, while, owing to the absence of pressure any obstruction in the pipes causes the siphoning action to stop and the filling material to cease to flow. The resulting blockage allows the concrete to set in the piping and accordingly the filling process requires to be suspended until the pipes have been dis-r mantled and cleaned. On the other hand the employment of a rampump is open to the objection that it operates only slowly and also involves the use of large quantities of and continuously through pipes into the cavities to be dealt with by means of a low Specification of Letters Patent.

Patented Sept. 27, 1921.-

1918. Serial No. 235,554.

to be fed into the cavities by means of a rotary or centrifugal pump and the piping is also connected up to a high pressure supply system, involving, for example, the use of a ram pump, provision being made for indieating the pressure prevailing in the pipes durin the filling operation in order that the h1gh pressure system can be employed when necessary. Instead of a ram pump being employed in the high pressure system, provision may be made for bringing into operation one or more supplementary-centrifugal or. rotary pumps, which may be located in series with one anotherand with the low pressure pump system, immediately the pressure indicator shows that a stoppage is likely to occur under the lower pressures then prevailing. When centrifugal pumps are employed it is preferred to use as the filling material a cheap form of concrete composed of cement powder and a finely ground and sieved material of approximately the same specific gravity as cement powder, such for example as furnace ashes or clinker, ground firebrick or the like,

preferably in the proportions ranging up to four parts by weight of furnace ash or the like to one part by weight of cement powder. If a series of centrifugal pumps are employed to i generate the necessary pressure the aforesaid improved concrete mixture can be employed during the entire filling o era tion but if a ram pump is employe for higher pressures 0 supply, provision is made when brin 'ng the rampump into operation for cutting off the supply of concrete and substituting therefor a supply of liquid cement. If desired both the ram pump and the centrifugal pump may be employed simultaneously, the ram pump in such cases being adapted when the; centrifugal pump is operating to feed "forward into the system of piping either a supply of fine cement or else a supply of water for the purs pose of assisting the flow of concrete 1nto the cavity which is -being filled. Owing to the fact that the aforesaid improved concrete is composed of materials which have apprbximately the same specific gravity there is no likelihood of the ingredients separating from one another under the influence of gravity while being fed through the system of pipes. I

In order that the said invention may be clearly understood and readily carried into effect the same will now be described more shaft and communicating with the cavity B branch pi e H fitted with a ram or piston pump I. oth'the pipes F and are provided with non-return valves J and J re spectively and communicate with a reservoir K fitted with a'stirrer L into which the filling material is fed. Toward the upper end of the main pipe D'a pressure gage M is fitted for the purpose of indicating the pressure prevailing in the main pipe D. The pumps G and I are driven in any convenient manner from any suitable source of power.

In operation, the filling material which is preferably constituted by the aforesaid improved form of concrete is fed intothe reservoir K. On the centrifugal pump being started the concrete is fed continuously and in large quantitiesat low pressure from the reservoir down the main pipe D into the cavity B., If desired the inlet end of the ram :pump may be laced in communication with a reservoir not shown) containing water or cement so as to deliver slowly a supply of water or cement into the, main pipe D simultaneously with. the supply of concrete. The centrifugal pump G delivers the concrete at "pressures up to about 60 lbs. per square inch, which is sufficient to overcome any ordinary obstruction which may arise in the piping and accor'din used until a large cavity such as cally filled. During th filling operation, however, when the water with which, the cavity is filled has to be forced out of the cavity into the surrounding soil, much. higher pressures arenecessary and at the proper moment (whichis indicated to the operator by the pressure registered on the dial of the gage M) the low pressure pump G is stoppedand the high pressure pump I if not already operatin is 1s practi now brought into operation and the fil mg operation is completed. In the arrangementshown in the drawing and while the ram pump I is o crating, pure cement (as before stated) is fed intothe reservoir K in 1y can be the kind first employed. e last stages of the 1. A method of consolidating and shut- I .ting off water from subterranean water bearing spaces which consists in establishing access to the space to be filled by-means of small diameter boreholes, providing pipes and valves located in said boreholes which are capable of withstanding the pressures generated during-the filling operation, connecting said pipes by means of a conduit to a system comprising a low pressure pump and a high pressure pump, providing, means for cutting into or out of the system either of said pumps, forcing a filling material into said space by means of said low pressure pump, and subse uently forcing into said space under a higher pressure by means of said high pressur pump a filling material different from the kind first employed.

2. A method of consolidating and shutting off water from subterranean water bearingspaces which consists in establishing access tojthe space to be filled by means of small diameter boreholes, providing pipes and valves located in said boreholes which are capable of withstanding the pressures generated during the filling-operation, connecting said pipes by means of a conduit to a system comprislng a IIllXlIlg apparatus, a

low pressure pump and a highpressure pump, roviding means for cutting into or I out of t e system either of said pumps, forcing a filling material into said space by means of said low pressure pump, and subsequently forcing into said space under a 7 higher pressure by means of said high ressure pump a filling material different mm 3. A method of consolidating and shut--- ting ofl water from subterranean water bearing spaces which consists inestablishing access to the space to be filled by means of A small diameter boreholes, providing pipes and valves located in said boreholes wh1ch forcing into said space under a higher pressure by means of said ram pump a fill' material difl'erent ployed.

4. A method-of consolidating and shutting oil water from subterranean water bearing spaces which consists in establishing access to the space to be filled by means of small diameter boreholes, providing pipes and valves located in said boreholes which are capable of withstanding the' pressures generated during the filling operation, connecting said pipes by means of a conduit to a system comprising a mixing apparatus, a low pressure centrifugal pump and a high pressure ram pump, providing means for cutting into or out of the system at will from the kind first emeither of said pumps without interrupting the continuity of the flow of filling material, forcing through the pipe system by means of said centrifugal pumpa mixture of cement and inert material of similar specific gravity so as to fill economically the main body of said space, and subsequently forcing into said space, by means of said high pressure ram pum pure cement grout immediately the centri ugal pump becomes inadequate to overcome the pressure in the pipe system, whereby the filling operation is rendered continuous and the water hear ing space made solid and dry thus enabling the excavation to be continued as though it were being carried. through normally dry ground which would. otherwise not be the case owing to the capability of the water bearing space discharging water into the area under treatment.

5. Means for filling subterranean water bearing spaces,

comprising a low ressure pump system adapted to force a fil ing material into said spaces, means for indicating the pressure prevailing insaid pump system, and a high pressure ump system adapted to force a difierent fil ing material into said spaces immediately an indication is given that the low pressure pump system is inadeuate, and that a blockage is occurring or is likely to occur.

6. Means for filling subterranean water bearing spaces, comprising a centrifugal pump for initially forcing a filling material into said spaces under pressure, and a ram pump system for subsequently forcing fil mg material into said spaces under a greater pressure.

7. Apparatus for filling subterranean water bearing spaces or cavities comprising ipes extending into said space or cavity, a ow pressure pump system for use in feeding concrete through said pipes into the cavity during the initial stages of the filling operation, a high pressure pump system for use in feeding'cement into the space or cavity during the tion, means vailing in the for indicating the pressure pre-' pipe system throughout the filling operation, and means for bringing into operation said high pressure pump system immediately an indication is given the low pressure pump system is inadequate to deal with the prevailing pressure.

8. Apparatus for filling subterranean water bearing spaces or cavities comprising a conduit, a low pressure pump system 'connected with said conduit, and a high'presfinal stages of the filling opera that sure pump system connected with the same conduit, for the purpose described.

9. Apparatus for ter bearing spaces or cavities comprising a conduit, 9. low pressure pump system connected with said conduit, and with a means for supplying a mixture of cement and aggregate to said conduit, means for indicating the pressure existing in said pump system, and a high pressure pump system connected with the conduit and with means for supplying cement thereto, for the purpose described.

ALBERT FRANQOIS.

filling subterraneanwa- 

